Telemetering system utilizing a variable self-checking code



July 14, 1964 G. l. VANCSA ETAL 3,141,150

TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING coma Filed May 25, 1959 10 Sheets-Sheet 1 Transmitter STd) PTb o PCTL3 IO Make Before Break Fig. IA

July 14, 1964 G. 1. VANCSA ETAL 3, 0

TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING CODE Filed May 25, 1959 10 Sheets-Sheet 2 July 14, 1 4 G. l. YANCSA ETAL 3,141,150

TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING cons Filed May 25, 1959 10 Sheets-Sheet 3 July 14, 1964 1, v cs ETAL 3,141,150

TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING CODE Filed May 25, 1959 10 Sheets-Sheet 4 July 14. 19.64 G. l. VANCSA ETAL 3,141,150

TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING cons Filed May 25, 1959 10 Sheets-Sheet 8 Ulo Rum Fig. 2C

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TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING CODE Filed May 25, 1959 10 Sheets-Sheet 9 FFUBc RU3d Rushq Rum Indicator Serial Decoder Printer Fig. 2D

July 14. 1964 G. 1. VANCSA ETAL 3,141,150

TELEMETERING SYSTEM UTILIZING A VARIABLE SELF-CHECKING com:

Filed May 25, 1959 10 Sheets-Sheet 10 TRANSMITTER RECEIVER MEASURING LINE DEVICE RELAY I PULSING REGISTER RELAY RELAYs .J COUNTER 5 CHECK RELAYs E RELAYS REGISTER DECODER RELAYS RELAYS PULSE SENDING INDICATOR RELAYS DEVICE l I l United States Patent M 3,141,150 TELEMETERING SYSTEM UTILIZING A VARI- ABLE SELF-CHECKING CODE Gyorgy I. Vancsa, East Pittsburgh, and William F. Cruess, Monroeville, Pa, assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed May 25, 1959, Ser. No. 815,518 11 Claims. (Cl. 340-1461) This invention relates generally to telemetering systems and has reference in particular to impulse systems for telemetering in coded form different values of metered quantities.

This invention is an improvement over the telemetering system disclosed in Patent No. 2,749,5 35, patented June 5, 1956, by W. F. Cruess.

The telemetering system of the hereinbefore mentioned prior patent scans an integrated count of values continuously stored in a decimal register system, and, upon demand, transmits a group of pulses for each registered digit, each group comprising a decimal number of pulses identical with the corresponding registered digit. This type of system includes means for detecting the presence of an extraneous pulse or pulses in each group of pulses if the toltal number of pulses in each group exceeds ten; however, because each group of pulses may have a different number of pulses in accordance with the decimal digit being transmitted, any group of pulses having a total number less than ten must be presumed valid, thus leaving a margin for error resulting from the addition or deletion of pulses such as may be produced by noise on the communication channel. Further the device of the prior patent utilizes a preliminary or unlocking code to guard against false readings due to channel noise.

Generally stated, it is an object of this invention to provide an inexpensive coding system having a fast, accurate, reliable mode of operation.

It is another object of this invention to provide in a telemetering system a fast accurate impulse transmission of metered values.

More specifically it is an object of this invention to provide in an impulse telemetering system a self-checking code for the metered values.

It is another object of this invention to provide in a telemetering system a transmitter which scans registered digits and transmits a self-checking binary code corresponding to each digit.

It is a prime object of this invention to provide in a telemetering system means for continuously registering the integrated count in plural digit form, which register ing means cooperates with a register scanning means to establish the self-checking binary codes to be transmitted for each digit of the registered count during a register scanning operation.

For additional objects and a more complete understanding of the nature of this invention, reference is made to the following description which may be read in conjunction with the accompanying drawings, in which:

FIGS. 1A through 1E taken collectively are a schematic diagram of one embodiment of a telemetering transmitter embodying this invention;

FIGS. 2A through 2D taken collectively are a schematic diagram of one embodiment of a telemetering receiver associated with the transmitter of FIGS. 1A through 1E;

FIG. 3 illustrates the manner in which FIGS. 1A through 1E and 2A through 2D are to be placed relative to each other, and when so positioned they represent the complete circuit diagram of a telemetering system embodying the present invention.

3,141,150 Patented July 14, 1964 ICC FIG. 4 is a code chart illustrating a binary self-checking code utilized in this invention.

Generally stated, the apparatus for carrying out the stated objects is comprised of a counter for continuously counting the impulses as provided by a primary measuring device such as a Watt-hour meter, a continuously op erating transmitter register which stores in plural digit form the integrated count supplied by the counter, a transmitter which scans the count stored in the transmitter register and which transmits a self-checking binary coded group of signals for each registered digit of the integrated count, a receiver which receives and checks the signal codes, and a receiver register which decodes and stores the checked signals and operates indicating lamps and printers of different types.

The coding utilized in this telemetering system is a standard type and is known in the coding art as a binary self-checking code. Generally stated, in a self-checking binary signal system of this type, a set of different combinations of two different types of signals are chosen so that a system of even-or-odd checks of the total numbers of the two types of signals of the code indicates the presence of errors. Herein, each code contains five signal intervals, the first four signal intervals carrying the coded information corresponding to a decimal digit, while the fifth signal interval provides the check on the corresponding four digits and is chosen according to the combination of the first four digits so that the total number of one type of signal is even. This is illustrated in FIG. 4 showing the last signal or X column as the check signal for the first four signals of each code. In this coding system, S designates a short pulse while L designates a long pulse, thus establishing the two different types of signals. It is to be understood that other kinds of relatively different signals may be employed, such as those of different polarity or dilferent frequency, or impulses which are present in some signal intervals and absent in other signal intervals. Ten of the sixteen possible different combinations of L and S signals in a four signal interval code are illustrated. As shown, each code corresponds to a decimal number, zero through nine. For each combination of four L and S signals, the last or X signal interval is chosen to be either an L or S signal to make the total number of Us in each five signal code even. Thus, a single error in any signal group will result in an odd number of Us and thus can be easily detected. It is to be noted that each of the ten selected codes of Chart 1 have exactly two Us This permits a somewhat better check than a straight odd-even check in that most double errors may be detected, as well as single errors, since two errors must be of an opposite nature to escape detection. The system for checking received codes will be hereinafter described in detail.

In this specification each relay coil is identified by a reference character suifixed by a small case letter indicating the total number of pairs of contacts associated with the corresponding coil, excluding the contacts of the stepping levels, if the coil is one of those serving as part of a stepping relay. For example, in the identification of register stepping relay U/ d in FIG. 1E, the small case letter "(2 indicates that the coil U operates contact pairs Ua, Ub, Uc and Ud. It is to be noted that coil U also controls three stepping levels, ULl, UL2 and UL3 in the counter A and in the register A, each stepping level having a bank of contacts or points, as shown. These additional stepping levels and contacts are not included in the small case letter "d of the register stepping relay U/d since the number of stepping levels and their relative locations on the drawings is easily seen at a glance; moreover, the stepping level reference characters are coded to relate to the parent coil. For example, in the stepping levels UL1, UL2 and UL3 the first character U relates to coil U, the other characters L2, L3 indicate the different levels of the same stepping switch 6U,1

The stepping switches are of a standard type which steps a movable contact arm from one contact or point to the next succeeding contact on the same stepping level at the termination of each pulse across the corresponding coil, all levels of the stepping switch operating simultaneously and in step. Each stepping level is shown with its movable contact arm in the zero or on-normal position so that at the end of the first pulse across the corresponding coil, the movable arm will step counterclockwise to the number 1 contact position, Each stepping switch includes at least one pair of on-normal contacts which operate only when the stepping switch is in the on-normal or zero position. For example, stepping relay U includes a pair of contacts Ua and U as onnormal contacts, the contacts Ua opening only when the stepping switch is in the on-normal position, while contacts Uc close only when the stepping switch is in the onnormal position. The contacts Ub and Ud of stepping switch U operates each time the coil U is energized.

Referring generally to the drawings, it will be seen that the impulse producing system, comprised of pulsing relays 1 and 2, provides output pulses to operate a counting system in response to output pulses provided at impulsing contact IM by a measuring device (not shown) such as a watt-hour meter. The counting system is comprised of stepping relays U, T, H, TH, TTH and HTH representing respectively units, tens, hundreds, thousands, ten thousands and hundred thousands, which are connected to operate in decade through their respective .counting levels UL1 through HTHLl, each level comprised of a bank of fixed contacts or points sequentially contacted by a movable contact arm as the counting progresses. The counter thus provides a continuous integrated count of the number of pulses provided initially by the measuring device. A register system continuously registers the integrated count and is comprised of a plurality of pairs of contact banks or levels UL2 and UL3, through HTHLZ and HTHL3, each pair corresponding to and operated by the stepping relays U through HTH, respectively, so that the registered count is constantly the same as the integrated count of the counter. Thus, the contacts or points zero through 9 of each register level effectively constitute indicating means corresponding to the respective decimals zero through nine, while the movable contact arm is etfectively an indicator selector means positioned by the counter system. A transmitter is provided to send a self-checking binary code comprised of five pulses for each digit registered, and includes a start relay ST which locks itself in in response to operation of a read-out pushbutton R0 and completes a circuit to energize either a short pulse relay S or a long pulse relay L, depending on whether or not the pulse control relay PC is deenergized or energized, respectively. The read-out pushbutton RO provides the additional function of energizing interconnecting relays I1 and 12 (FIG. 1D) to connect the transmitter to the register system. The long pulse relay L is of the delay release type taking a relatively longer time to release than the short pulse relay S. A pulse sending relay PS is provided to send each pulse in response to operation of either the short pulse relay S or the long pulse relay L and at the same time deenergize relays S and L so that if the long pulse relay L is the energizing relay, the sending relay PS will remain energized for a longer time than short pulse relay S to thus send a long pulse. A pulse counting stepping relay PCT responds to the individual operation of both the short pulse relay S and the long pulse relay L to step its pulse count level PCTLl from point to point as the pulses are transmitted, to thus sequentially connect the pulse control relay PC to different groups of contacts of the units register levels UL2 and UL3 to complete a circuit for energizing the pulse control relay PC for two difierent ones of the five pulses, depending on the position of the movable contact arm in the register levels UL2 and UL3. A code counting stepping relay CC controlled by counting levels PCTL2 and PCTL3 of the pulse counter PCT operates after each five pulses to step its code counting level CCLI for sequentially connecting the transmitter to the next succeeding register element such as the tens element. The pause timing relay PT is provided to be energized after the fifth pulse count by the pulse count relay PCT to prevent further energization of the short pulse relay S and the long pulse relay L until the transmitter has connected to the next digit of the register system. At the termination of the transmission of a binary code for each digit of the register system, the code counting relay CC energizes reset relay RE which is provided to rest or deenergize the start relay ST and the inter-connecting relays I1 and I2. Thereafter, a second register system A may be automatically connected to the transmitter through cooperation between the interconnecting relays l1 and I2 and I3 of the first system and interconnecting relays 11, I2, 13 of the second register system A, in a manner to be hereinafter described in detail.

The receiving portion of the invention includes a line relay RL and an auxiliary line relay RLX, the latter being of the time delay release type, which respond to the length of incoming pulses to energize appropriate ones of five preliminary coding register relays PR1 through PR5 for each long pulse received, each register relay corresponding to one of the signal intervals in the five signal interval binary code. A pulse count stepping relay RPCT sequentially connects the line relay RL and the auxiliary line relay RLX to control each one of the preliminary code relays as the impulses are received and deenergizes the coding relays at the end of each five signal intervals to prepare them for temporarily registering the next group of pulses. A parity check circuit controlled by the preliminary registering relays is provided to complete a circuit to the main register groups RU, RT, RH, RTH, RHTH, RSU and RST only if a valid code is received. The main register groups are each comprised of four register relays RUl-RU4 through RST1RST4, respectively, to register eight digits in binary form. A code counting stepping relay RCC is provided to operate at the end of each five pulses to sequentially connect the preliminary register relays PR1 through PR4 to operate the next succeeding group of main register relays. Appropriate decoding trees comprised of contacts of the registering relays of each group are provided to check the codes and operate appropriate decoding indicator means, such as a printer or lamps, to indicate in decimal form the digit received in binary code. Alternatively, there is provided printers of commercially available types to operate and provide a printed record of the received digits. A reset relay RRE is provided to automatically reset the receiver at the end of a transmission period. The main register relays remain operated until reset by reset button RB, or until a new valid code is received, whichever occurs first.

Referring particularly to FIGS. 1D and IE it will be seen that the counting circuit is comprised of a plurality of stepping relays U, T, TH, TTH, and HTH representing respectively units, tens, hundreds, thousands, ten thousands and hundred thousands, all interconnected to decimally count impulses provided by the closing of the contact IM of an impulsing device (not shown) such as a watt-hour meter which may be adapted to operate through suitable gears or the like to actuate the contact arm 1M so as to produce one impulse per unit registration whether it be kilowatt or megawatt hours. Each time the impulsing means closes its contacts IM, pulsing relay 1 energizes to close contacts 1b for energizing auxiliary pulsing relay 2 which opens contacts 2a to deenergize pulsing relay 1. Auxiliary pulsing relay 2 then locks in through contacts 2b and IM so as to maintain pulsing relay 1 in a deenergized condition. When contacts 1M reopen, auxiliary pulsing relay 2 is deenergized, thus closing contacts 2a and conditioning pulsing relay 1 for the next pulse actuated by the closing of contacts IM. In this manner pulsing relay 1 is energized for a single short period each time contacts 1M are closed.

Each time pulsing relay 1 operates in the manner described above, it closes and opens contacts 1d causing energization and deenergization of the units register and counting relay U in counter A which moves its stepping arm of stepping level ULl to the next succeeding point for each deenergization of stepping switch U. Thus, at the termination of the first pulse, the stepping switch moves from the on-normal or zero position to contact 1 of stepping level ULI, thereafter moving one step for each pulse until at the end of the ninth pulse, the moving contact arm steps to contact 9 of unit level UL thus completing a circuit to stepping coil U through its own contacts Ud. Stepping switch U then energizes and immediately opens its contacts Ud to deenergize and step its contact arm to contact 10 of stepping level UL1 to set up a circuit through contacts ROXa and Ilc to the tens stepping switch T. Thereafter, contacts 1d close for the tenth pulse, stepping switches U and T pick-up together and when contacts 1d of the pulsing relay release at the end of the pulse, the units stepping relay U steps to the on-normal position preparatory to beginning another count, and the tens stepping relay T simultaneously steps to contact number 1 on stepping level TLI, thus indicating a count or" the first ten impulses. In a similar manner, the tens stepping switch and its level TLl responds to full counts of the units stepping switch U to count each additional ten impulses until the tens stepping switch T reaches contact 9 on stepping level TLl where it takes an additional step to set up subsequent operation of the hundreds stepping switch H in the same manner as the units stepping U set up operation of the tens stepping switch T as previously described. Each stepping relay H, TH, TTI-I, and HTH is connected to be operated in decade in the manner described for the units and tens stepping relays to thus provide a continuous count of the number of impulses occurring at the impulse contact IM.

If it is desired to reset the counting means to a zero count, there is provided for this purpose a homing switch HS which may be held closed to complete a circuit from any suitable direct current source to energize the units stepping relay U through on-normal contact Ua and interrupter contact Ub. The stepping relay U interrupts its energizing circuit through its contacts Ub, thus providing its own pulsing input and causing a rapid, continuous stepping operation of stepping level ULl until the moving contact arm reaches the on-normal or zero position so that on-normal contact Ua opens to prevent further energization of the stepping relay U. An additional on-normal contact Uc of stepping relay U then closes completing a circuit through homing switch HS and through the tens stepping relay T which operates in similar fashion through its interrupter contacts Ta to step to the zero position thus opening its on-normal contacts Tb to prevent further self-stepping operations, and also to close its on-normal contacts Tc to set up an energizing circuit for the hundreds stepping relay H. In this manner all the stepping relays may be reset to zero merely by closing homing switch HS. As will be hereinafter described in detail, when a readout operation is initiated by operation of read-out switch R0, the interconnecting relays I1 and I2 are operated to connect the register A to control operation of the transmitter in accordance with the registered count. It is necessary to prevent operation of the counter and register during a read-out operation to avoid the sending of invalid or inaccurate codes, but at the same time it is desirable to maintain a full count of all incoming impulses from the watt-hour meter. This is achieved through pulse storage relay ROX which is set up for operation by contacts Ila of interconnecting relay I1 which completes a circuit through contacts 1d, movable arm of count level ULl, point 10 of count level ULl and contacts ROXa to energize pulse storage relay ROX when the units count level ULl reaches the point 10 after the interconnecting relay I1 is operated for a read-out operation. Contacts I10 interrupt the previously described energizing circuit for the tens count relay T. Pulse storage relay ROX locks-in through operation of contacts ROXc in series with contacts Td of the tens relay T. Whereafter, if an additional impulse is provided by impulse contacts IM, as previously described pulse storage relay ROX operates to close contacts ROXb, setting up an operating circuit for the tens relay T through contacts ROXb, Ilc. Thereafter, when interconnecting relay I1 is deenergized at the end of a transmission, contacts close, completing the previously described circuit to operate tens relay T, which in turn opens its interrupting contacts Td to drop out pulse storage relay ROX. In this manner, the operation of the tens relay T is delayed until after termination of a read-out operation, assuring accurate coding, and at the same time preserving the full count of impulses occurring at impulse contacts IM.

In FIG. 11) there is shown an additional impulsing contact IM which is responsive to a different and separate impulse producing means (not shown) and which operates pulsing relays 1' and 2, and a counting means A, all identical in structure and operation to the corresponding structure as previously described.

The register is comprised of a plurality of pairs of digit register levels UL2 and UL3, TL2 and TL3, HL2 and HL3, THLZ and THLS, TTHLZ and TTHL3, and, HTHL2 and HTI-iLfv, each pair operated by the previously mentioned stepping relays U, T, H, TH, TTI-I, HTH, respectively, as the incoming impulses are counted in the manner previously described. As will be hereinafter described in detail, the contacts or points or each pair of register levels are scanned by counting stepping relay PCT which counts the number of signal intervals in each transmitted binary code and simultaneously cooperates with the register level contacts to energize a pulse control relay PC for determining the binary code corresponding to the decimal digit as registered in the register levels. The register levels are identical in structure and operation, accordingly, only the units register levels ULZ and UL3 are shown in detail while the remaining register levels are shown in block form for convenience of illustration.

Referring now to FIG. 1A there is disclosed a trans mitter operable to be connected in sequence to each register element of each register system to send binary codes corresponding to each of the registered decimal digits. A read-out pushbutton momentary switch RO is provided to complete circuits to the interconnecting relays II and I2 for connecting the transmitter first to the register A, and to simultaneously energize start relay ST for starting operation of the transmitter. Operation of the read out pushbutton R0 (FIG. 1D) energizes interconnecting relays I1 and I2 through contacts REb, 8Tb, pushbutton R0, and contacts 10 to connect the transmitter to register A in a manner hereinafter described in detail. If the contacts 1c are open, as they are between impulses, the lnterconnecting relay I2 operates through the described energizing circuit to close its contacts 12a completing a circuit paralleling 12a (FIG. 1A) to energize start relay ST which starts operation of a transmitter. In a manner to be presently described in detail, the transmitter responds to operation of the start relay ST to automatically begin sending consecutive pulses, all pulses being of short time duration unless the signal control relay PC is energized at the beginning of any particular pulse, in which event that particular pulse will be long. Therefore, in order that the transmitter may transmit two pulses of a long time duration in each five pulses transmitted, so as to provide the coding shown in Chart 1, it is necessary that 7 the pulse control relay PC be energized twice during each consecutive group of five pulses.

The energization of the pulse control relay PC at the right time to provide the binary coding of Chart 1 for any particular registered decimal number on each register element U, T, H, TH, TTH, HTH, is provided by the pulse count stepping relay PCT in cooperation with the register A. As will be presently described, the sending of each pulse by the transmitter operates the pulse counting stepping relay PCT which steps the movable contact arm point-by-point around the contact bank of pulse control level PCTLI for each pulse sent by the transmitter and in this manner sequentially connects the signal or pulse control relay PC to different contacts on the register levels UL2 and UL3 to detect the location of the long pulses in two of the five signal intervals of the first five signal interval code to be sent, as governed by the register. As will readily be seen when the codes of Chart 1 are compared with the particular contacts of the register levels UL2 and UL3 which are connected in series with each ditferent contact of the pulse counting level PCTLI as the pulse count relay PCT operates, the signal control relay PC efiectively sees simultaneously the first signal interval of all ten codes when the count level PCTLl is closing its zero contact, sees the second signal interval of all ten codes when the pulse count level PCTLl is closing its number 1 contact, and similarly sees the third, fourth and fifth signals of all ten codes when the count level PCTLl closes its contacts two through four, respectively. For example, when the pulse count level PCTLl closes its zero or normal contact, pulse control relay PC is connected simultaneously through conductor 16 to contacts 6, 7, 8 and 9 of register level UL2 so that if the movable contact arm of level UL2 is positioned on any of these contacts, a circuit hereinafter described will be completed through the movable contact arm to energize pulse control relay PC so as to provide for sending a long pulse as the first signal of the binary code. Referring to Chart 1 it will be seen that each of the decimal numbers 6, 7, 8 and 9, all have long pulses as the first signal in their respective codes, and inasmuch as these particular contacts correspond respectively to decimal counts of 6, 7, 8 and 9 of the counter and the register, it is seen that the position of the movable arm of register level UL2 determines the location of one of the two long pulses in the five pulse group, while the position of the movable arm on level UL3 determines the position of the other long pulse in the same group of five pulses. Inasmuch as the particular codes in this embodiment include two long pulses, two register levels are provided for each register element so that in any one code no point on the same register level will be connected to more than one of the conductors 16-20, and in this manner maintain isolation of conductors 162tl with respect to each other to prevent the occurrence of unscheduled long pulses that would otherwise arise through sneak circuits that would be established if only one register level were used for each code. It is seen that the utilization of only one register level for each register element to send two long pulses for each code would necessitate the connection of each indicating point through 9 of level UL2 to two of the conductors 162i), thus connecting each conductor at all times to all the others, resulting in the establishing of a long pulse for every signal interval for every position of the contact arm. Thus, even if only one code includes more than one long pulse, an additional level is necessitated to accommodate that code. Utilizing this type of decimal to binary coding, codes having any number of long pulses may be readily accommodated by merely providing each register element with stepping levels equal in number to the number of long pulses in the code having the largest number of long pulses.

To illustrate the manner in which the pulse count level PCTLl and the register levels UL2-UL3 cooperate to energize the signal control relay PC, and assuming the 8 number seven to be registered on register levels UL2 and UL3, it is seen that when the pulse count level PCTLl is on zero, a circuit is completed to energize signal control relay PC through conductor 16, contact 7, contact 12d, movable contact arm of register level UL2, diode DUZ, contact 13c of the operated interconnecting relay I3, conductor 26, the zero or normal contact of code counting level CCL1 of code counting stepping relay CC and contacts P8!) of pulse sending relay PS. When the pulse count level PCTLI steps to the number 1 contact, connecting the pulse count relay PCT to contacts 9 of the register level UL3, no circuit is completed to signal control relay PC since the movable arm of level UL3 is on contact 7. As the pulse count level PCTLl steps through the points 2, 3 and 4, the signal control relay PC is energized on the first and fourth pulses of the first five pulses in accordance with the code for registered number 7 count as set forth in Chart 1. This energization of signal control relay PC establishes a long pulse control operation for the transmitter for each of these two pulses in the first five pulse group.

When the start relay ST operates in response to the operation of pushbutton R0 at previously described, contacts STd close to complete a circuit through the short pulse relay S through normally closed contacts PCa if the pulse control relay PC remains deenergized, or alternatively, completes a circuit to the long pulse relay L through contacts PCb if the pulse control relay PC is energized. The operation of either the short pulse relay S or the long pulse relay L closes contacts Sa or La, respectively, to operate the pulse sending relay PS which closes its contacts PSc (FIG. 2a) to energize the receiver line relay RL.- At the same time, pulse sending relay PS opens its contacts PSa to deenergize the energized slow or short pulse relay S or long pulse relay L, which in turn open their contacts Sa or La to deenergize the pulse sending relay PS and thus terminate the particular pulse. It is seen that if the short pulse relay S is the energizing relay, the pulse is short, whereas if the long pulse relay L is the energizing relay, the pulse is long because of the delayed release of the long pulse relay L. A pair of contacts Sb and Lb of the short pulse relay S and the long pulse relay L, respectively, are parallel connected to pulse count relay PCT so that each energization and deenergization of either the short pulse relay S or the long pulse relay L will energize pulse count relay PCT to step its stepping levels. In this manner, pulse count level PCTLl operates to connect the signal control relay PC to the different contacts of the register levels UL2 and UL3 for each succeeding pulse in the manner previously described. At the end of the fifth pulse the pulse count relay PCT steps all its levels to the number 5 contacts. Pulse count level PCTL3 steps to contact number 5 completing a circuit through contact number zero of code count level CCL2 to operate pause timing relay PT. Pause timing relay PT operates code count relay CC through contacts PTc, and opens its contacts PTb to prevent further energization of either the short pulse relay S or the long pulse relay L. The code count relay CC opens its contacts CCa to interrupt its energizing circuit to thus step each of its contact levels to the number 1 contact. The code count level CCLZ steps to its number 1 contact thus opening the energizing circuit for pause timing relay PT which closes its contacts PTb to again condition the long pulse relay L and the short pulse relay S for energization in the manner previously described. At the same time code count level CCL1 steps to the number 1 contact, thus disconnecting the units register levels UL2 and UL3 from the transmitter and connecting the tens register levels TL2 and TL3 to the transmitter. The code count level CCL3 in stepping to the number 1 contact completes a set-up circuit through contacts 5 of pulse count level PCTLZ for the energizing of the short pulse relay S or the long pulse relay L at the beginning at the first pulse of the second code group. In this manner transmission of the first binary coding of the units register level is completed. The transmitter is now connected to send a second group of five pulses in binary code in accordance with the registered digit in the tens group with the pulse count level PCTLl continuing its count of the second group of pulses through its contacts through 9 which are sequentially connected to the ditferent group of contacts of the tens register levels TL2 and TL3 in the manner previously described with respect to the connection of the contacts zero through four with the units register, the coding being identical. The transmitter continues transmitting a group of five pulses for each of the registered units, tens, hundreds, thousands, ten thousands and hundred thousands with the code count level CCL1 sequentially stepping from one contact to the next for each code of five pulses to connect the transmitter in sequence to each of the registered digits until at the beginning of the TTH code, level CCL1 step to contact 5.

At the end of the last code, code count level CCL1 steps to the number 6 contact which may be connected to energize th reset relay RE or which may be connected to cause the transmitter to send an additional code as a fixed number identifying the particular watt-hour meter or the station number which instituted the count. If it is desired to send an additional fixed number to identify the station, such as the number 5, the number 6 contact of code count level CCL1 is connected directly through conductor 28, and parallel connected diode pair DSU to contacts number 1 and number 2 of the pulse count level PCTLI so that a circuit will be completed through pulse control relay PC on the second and third signal intervals of the seventh code group, thus sending the binary code for the decimal number five. If two station numbers are desired, the number '7 contact of code count level CCL1 may be likewise connected directly to two of the number 5 through 9 contacts of the pulse count level PCTLl.

Reset of the transmitter at the termination or" a transmission of all codes for the registered digits of register A and the additional digits including the two station signals, the number 8 contact of code count level CCL1 completes a circuit through contacts PS1; to energize reset relay RE which locks in through its contact RE! and at the same time closes its contacts REc to energize the code count relay CC which interrupts its energizing circuit through its own interrupter contacts CCa to continue stepping to the zero or normal position where it opens its on-normal contacts CCb to terminate the stepping action, and closes contacts CCa to energize pulse count relay PCT which continues tripping to the zero or normal position in a similar manner. When the code count relay CC and the pulse count relay PCT reach their respective on-normal positions they respectively close the contacts PCTc and CCc to shunt and thus deenergize reset relay RE, thus setting up the transmitter for transmission of additional binary codes.

The reset relay RE operates to serve the additional function of disconnecting the transmitter from register A and connecting the transmitter to register A for transmission of the next group of binary codes corresponding to the registered digits of register A.

As previously described, operation of the read-out pushbutton R0 energized interconnecting relays I1 and 12, the latter operating to close contacts 12a completing a circuit through contacts REb, STb, conductor 13, switch R0, contacts 10, 12a, and conductor 12 to energize start relay ST. Relay 12 also closes contacts 12b completing an energizing circuit for one coil 13A of dual coil relay I3A-I3B. The interconnecting relay I3 closes contacts 13a in series with its coil 13b having no immediate effect, and at the same time closes contact 1312 setting up an energizing circuit for the interconnecting relays I1, 12 and 13 of the counter A through contacts STa, conductor 14, contacts 13b and 1's; however, the energization of start relay ST opens contacts STa to prevent completion of this circuit. When reset relay RE operates in the manner previously described, contacts REE; are opened to open the lock-in circuit for start relay ST which deenergizes to close its contacts STb to complete the set-up of an energizing circuit for interconnecting relays I2, and 13' through the previously closed contacts 13b of interconnecting relay 13. The operation of relay RE closes contacts RE: which complete a circuit through conductor 14, and previously closed contacts 13a to maintain interconnecting relay coil 13B energized as interconnecting relay I1 and 12 drop out because of the opening of contacts STb as starting relay ST is dropped out contacts Ild, Ile, 11g, 12c, I21, 12g and 1211 open to disconnect the transmitter from register A. When reset relay RE drops out in the manner previously described, contacts REb close to complete a circuit through contacts STb, conductor 13 and 13b to energize interconnecting relays I1, I2 and 13', and at the same time contacts REa open to open the energizing circuit for interconnecting relay 13 to eliminate the set up circuit for the interconnecting relays 11 and 12. The operation of interconnecting relays I1 and I2 closes contacts Ild, He, Iig, lZc, IZf, I2'g and 1211 to connect the transmitter to register system A in the same manner that interconnecting relays I1 and I2. connect register A to the transmitter through contacts 11d, He, Ilg, 12c, 12f, 12g and 12h. At the same time, operation of interconnecting relays Ill, 12 closes the contacts I2a to complete an energizing circuit through conductor 12 for start relay ST. Transmission of the binary codes corresponding to the register digits of the register A now begins.

The receiver line relay RL (FIG. 2A) operates each time the pulse sending relay PS in the transmitter closes its contact PSc in series with line relay RL. The line relay RL remains energized so long as contacts PSc of the pulse sending relay are closed, and operates to open its contacts RLa. to deenergize the auxiliary line relay RLX, which is of the slow to release type, and at the same time operates its contacts RLb to set-up a circuit for energizing the first preliminary register relay PR1. If the first pulse is long as in the binary code for the decimal number 7, contacts RLa remain open for a time suflicient to deenergize the auxiliary line relay RLX which closes its contacts RLXa in series with contacts RLb of line relay RL to thus complete a circuit through the zero contact of the pulse count level RPCTLZ to energize the preliminary code register relay PRl, which then locks itself in through holding contacts PRlc in series with contacts RLc of the line relay RL. Conversely, if the received pulse is short, line relay RL energizes and deenergizes before auxiliary line relay RLX has sufiicient time to fully release, thus maintaining the previously described circuit to the preliminary register relay PR1 in an incomplete condition through contacts RLXa which remain in an open condition. Thus, it is seen that when a long pulse is received, the corresopnding one of the preliminary register relays PR1 through PR5 is energized, whereas if a short pulse is received, the corresponding preliminary register relay remains deenergized. An additional pair of contacts RLd of line relay RL operate the pulse counting stepping relay RPCT each time a pulse is received. In this manner as the first pulses are received, the pulse count relay RPCT steps the pulse count level RPCTL2 through contacts zero through four to sequentially set-up an energizing circuit for each of the corresponding preliminary register relays PR1 through PR5 for each long pulse received. For example, for the decimal number 7, the binary coding is LSSLS, in which event only the preliminary register coding relays PR1 and PR4 will be energized and locked in through their respective holding contacts PRlc and PRdb.

A parity check sytsem comprised of open and closed contacts of the preliminary registered coding relays PR1 through PR5 operates a check normal relay CRN when ill the received code is one which includes an even number of long pulses and an odd number of short pulses. This includes all ten of the codes of Chart 1, each having only two long pulses, plus the six remaining codes of the sixteen possible combinations of long and short pulses previously discussed with respect to self-checking codes, which six codes each include four long pulses. However, it is highly unlikely that errors in any of the preassigned codes of Chart 1 would produce any of these additional six codes so that the code check circuit is highly effective in checking for errors. In the event the received code is not one of these sixteen codes, the check system alternatively operates the abnormal check relay CRA. For example, for the digit 7, preliminary coding relays PR1 and PR4 are energized to operate contacts PRlla and PR4a through PR4e, respectively. This completes a circuit to check normal relays CRN through contacts PRla, PRZa, PRSa, PR lb and PRSd. If one of the signals had been reversed, such as the fifth signal, PR5!) would have closed to complete an energizing circuit to the abnormal check relay CRA rather than to the normal check relay CRN.

It is to be noted that the odd-even check system will pass any five signal interval code having either two or four long pulses or Ls, and will reject any five s1gnal code having zero, one or three long pulses. Thus, the occurrence of a single error in any code such as to change a long pulse to a short pulse or a short pulse to a long pulse will be rejected. Similarly, the occurrence of a double error changing two long pulses to two short pulses will provide zero long pulses and will also be rejected. However, the occurrence of a double error changing two short pulses to two long pulses will pass undetected since the total of long pulses in this instance is four. S1m11arly, the occurrence of a double error converting one long pulse to one short pulse and converting one short pulse to one long pulse will pass undetected since the total number of long pulses remains even. As will be hereinafter described in detail, the decoding or translating systems act as auxiliary check systems which reject any code having four long pulses. Accordingly, only double errors of an opposite nature can be passed through the receiver to provide an erroneous operation. Since the occurrence of a double error comprised of a long pulse and a short pulse is extremely unlikely, the parity check system and the auxiliary check system collectively provide substantially complete protection against single and double errors.

When check normal relay CRN operates to close its contacts CRNb, a circuit is completed to energize the code count relay RCC through contacts CRNb, the zero contact of code count level RCCL6, contact number 5 of pulse count level RPCTLI, contacts RPCTa, CRAa, and AREg. Also, when relay CRN operates, contacts CRNg open to deenergize all sealed-in main register relays. T hereupon, code count relay RCC immediately operates to interrupt itsenergizing circuit at contacts RCCb and thus step all code count levels to the number 1 contact to complete circuits for energizing appropriate ones of the main register units relays RU1 through RU4 of register RU in accordance with the registered long and short signals on the preliminary register relays PR1 through PR4. Specifically, when code count level RCCLS steps to the number 1 contact, a circuit for the main unit register is set-up from positive through contacts AREg, CRAa, RPCTa, number 5 contact of pulse count level RPCTLI, the number 1 contact of code count level RCCLS conductor 30, through parallel connected contacts PRld, PRZg, PR3g, and PR -t-g of the preliminary register relays PR1 through PR4, respectively, through the number 1 contact of each code count level RCCLI to RCCL4 to the main register relays RU1 to RU4, respectively of units register RU. Thus, inasmuch as the preliminary register relays PR1 and PR4 have been previously energized upon receipt of the digit 7 binary code in the manner described above, their respective contacts PRld and PR4g are closed to complete the circuits as above described to main register relays RU1 and RU4, which register relays lock-in through their contacts RU1!) and RU4Z2, respectively, while at the same time opening the energizing circuits at contacts RUIa and RU4a, respectively. The lock-in circuit for the main register relays RU1 through RU4 extends through relays RU1 through RU4, contact RUlb through RU4b, lamp reset switch LR, and contacts CRNa to positive.

At the end of the fifth pulse, pulse count level RPCTL3 steps to the number 5 contact opening the previously described lock-in circuits for the preliminary register relays PR1 through PR5; however, the preliminary register relays remain locked-in through contact RLc of line relay RL so that the preliminary register relays which are energized remain so energized until the beginning of the next five pulses when the contacts RLc reopen so that in the interim they may initiate energization of the appropriate main register relays, as described, but return to the deenergized condition preparatory to registering the next code.

As the second group of five pulses is received for the tens register, the pulse count level RPCTLZ steps through contacts numbers 6 through It) sequentially connecting the preliminary register relays PR1 through PR4 to be controlled in turn by the line relay RL and the auxiliary line relay RLX in the manner previously described, but in accordance with the particular binary code being received for the tens digit. At the end of the second code, check normal relay CRN operates in response to the valid code to energize the code count relay RCC through contact number 10 of pulse count level RPCTLI, and contact number 1 of code count level RCCL6, whereafter code count relay RCC steps all levels to the number 2 contact, thus completing a circuit through contact number 10 of pulse count level RPCTLI and contact number 2 of code count level RCCLS to appropriate ones of the parallel connected contacts PRld, PRZg, PRSg and PR4g of the two energized relays of the preliminary register relays PR1 through PR4 and associated number 2 contacts of code count levels RCCLl through RCCL4,

. respectively, to energize corresponding ones of the main register relay of the tens main register T in the same manner as the contacts number 1 of each code count level RCCLI through RCCL4 energizes main register relays RUl through RU4 of the units register, as previously described.

At the end of the second group of five pulses, the pulse count relay has stepped all levels to the number 10 contact. When pulse count level RPCTL3 steps to the number 10 contact, a circuit is completed to energize pulse count relay RPCT from negative, through relay RPCT, through contacts RPCTc, contact number 10 of the pulse count level RPCTL3, contacts RLc and contacts AREg, whereupon pulse count relay RPCT interrupts the energizing circuit at contacts RPCTc and steps to the zero or on-normal contact of all levels thus preparing to begin an entirely new cycle at the beginning of the third code, which is the hundreds code.

In this manner all five codes of the Watt-hour meter and the two additional codes of the station identification number are received and registered in the registers RU, RT, RH, RTH, RTTH, RHTH, RSU and RST, where SU and ST indicate station unit identification and station tens identification, respectively. The code counting levels have stepped through the number 7 contacts.

When the pulsing stops, line relay RL ceases operation, thus maintaining contacts RLe in an open condition permitting time delay release auxiliary reset relay RRE to fully release whereupon contacts RREa are closed to energize reset relay ARE which locks-in through contacts AREd and at the same time completes homing circuits for pulse count relay RPCT and code count relay RCC through contacts AREb and AREa, respectively. The

13 pulse count relay and the code count relay each step to zero through operation of contacts RPCTc and RCCb, respectively, whereupon the on-normal contacts RPCT b and RCCc, are opened to terminate the home-stepping operation. An additional contact ARE) of reset relay ARE reenergizes auxiliary reset relay RRE. When the pulse count relay RPCT and the code count relay RCC step to the Zero positions, contacts RPCTa and RCCd close to complete a shunt circuit around reset relay ARE, which drops out. The receiver is now reset and in condi- Zen to receive the next code from the transmitter register A conventional decoding or translating tree may be provided for operation by each of the main register groups RU, RT, RH, RTH, RHTH, RSU and RST, to translate the register binary code to its corresponding decimal digit indication, as shown in FIG. 2D. For example, in the units register, the digit 7 is registered through energization of register relays RUI and RU4, as previously described.

Thus, in the translating tree for the units register, output number 7 is energized through contacts RUlb, RUZc, RU3e and RU4h. The outputs through 9 may lead to an indicating system, such as a lamp for each lead or a parallel output printer of any commercially available design for printing the decimal information.

It is to be noted that inasmuch as the decoding or translating trees respond only to the first four digits of any code, and inasmuch as none of the first four digits of any code includes more than two long pulses, the decoding tree rejects codes having four long pulses and thus comprises an auxiliary check system for detecting the double error of the type which changes two short pulses to two long pulses. As previously described, the parity check system passes double errors of this type. In this manner the decoding tree functions as an auxiliary code check cooperating with the parity check system.

The operation of the indication system by the register relays occurs at the end of the transmission when the code counting relay RCC steps to the number d contacts of stepping levels RCCLl through RCCL S, completing a circuit through diodes RDLRDG respectively, conductor 31, contacts LRa, to lamp relay LR which operates and locks in at contacts LR!) and also closes contacts LRc (FIG. 2D) to complete a circuit to a source of voltage, such as a battery, for operating the indicator system. The lamp relay drops out to reset the indicator system when the next valid code is received to operate the check normal relay CRN which interrupts the lamp reset relay LR at contacts CRNa.

Operation of a serial decoder printer may be provided through secondary register relays A, B, C, and D (FIG. 2A) which operate to duplicate the indications of the preliminary register relays PR1PR4 if the registered code is valid. Thus, when check normal relay CRN operates at the end of the first valid code, the secondary register relays are operated through a circuit from positive, through contacts ARI-3g, CRAa, RPCTa, the number contact of pulse count level RPCTLl, number 1 contact of code count level RCCLS, conductor 30, through each pair of contacts PRld, PRZg, PR3g and PR4g depending on which of the preliminary register relays are energized, through respective conductors 32-35 to the respective secondary register relays A through D to negative, each secondary relay being parallel connected with an output leading directly to a serial input printer, if desired. Each energized secondary relay operates to lock in through contacts Ab through Db, respectively, through conductor 30, and stepping levels RCCLS and RPCTLI and interrupts its energizing circuit at contacts Aa through Da, respectively. When the next pulse count be ins, pulse stepping level RPCTLI interrupts the locloin circuit, thus preparing the secondary relays and the serial input printer for the next code. A conventional decoding tree (FIG. 2D), similar to DRU through DRST, as previously described, is provided responsive to secondary relays A through D to operate a serial decoder printer.

The receiver includes a system for detecting errors in the number of pulses received.

When the total number of incoming pulses is less than five, the reset relay RRE is fully released at the termination of the pulses and the receiver resets in the manner previously described. No operation of the indicating system occurs under these conditions since lamp relay LR remains deenergized.

When the codes are valid but the number of impules is less than 40 for an eight digit number the reset relay ARE operates before the code count switch RCC attains the number eight contact, thus opening contact AREg to prevent any possible energization of a lamp relay LR through the energizing circuit previously described. Thus, since relay LR cannot operate there is no operation of the indicating system.

The receiver also includes a system for detecting invalid codes.

When the number of pulses is five or more, but the first five pulses do not provide a valid code as the fifth pulse is received the check system operates abnormal check relays CRA, in the manner hereinbefore described, which seals in through contact CRAb and contact AREg of reset relay ARE. As the abnormal check relay CRA operates, the circuit to pulse count relay RPCT was opened through contacts CRAc, thus preventing the further operation of the pulse count relay during the remainder of the impulses received. When the pulsing stops, the auxiliary reset relay RRE is released to initiate reset of the receiver in the manner previously described. No operation of the indication system occurs.

When an invalid code is received after the receipt of one or more groups of eight valid codes which have operated the indication system, the lamp relay LR is prevented from further operating by the abnormal check relay CRA as above described so that the failure of the indication system to operate provides a positive indication of invalid coding.

If desired, an indicator (not shown) such as a lamp may be connected to operate directly from an additional contact (not shown) of the abnormal check relay CRA, to indicate the occurrence of an invalid code.

From the above description and the accompanying drawings it will be apparent that there has been provided a telemetering system having a transmitter counter and register comprised of stepping switches for decimally counting and registering impulses and including a pulse counting stepping relay having its individual points of the counting level sequentially connected in each signal interval to all register points corresponding to preassigned codes having one type of pulse in the corresponding signal interval, so that when the movable contact arm or indicator selector is positioned on one of the indicators for the interval being counted, a signal control means is operated causing the transmitter to send a signal of said one type in the corresponding signal interval of the transmitted code. The decimal register system thus converts a decimal number to a preassigned five signal interval binary self-checking code having a predetermined number of two diiferent types of signals in a simple, efiicient, inexpensive manner.

If desired, this system may be readily adapted for use as a coding system in remote control apparatus merely by eliminating the counter and register stepping relays, and substituting a selector switch for the register levels of the stepping relays. If only nine control points are involved, a single selector switch will suffice to provide the nine self-checking binary codes, or alternatively, selector switches may be gauged or operated individually to provide the full range of code combinations of six or more selector levels corresponding to the six transmitter register levels in the telemetering system. At the remote station the register relays could operate control relays, as desired.

Inasmuch as certain changes may be made in the above described description and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the above description and shown in the accompanying drawings shall be considered as illustrative and not in a limiting sense.

We claim as our invention:

1. In a coding system for selectively transmitting a plurality of different codes: each code having the same number of signal intervals, each code comprised of a different combination of a first and second type of signals representing a decimal digit, at least one of said codes having more than one signal of said second type; a plurality of selector positions, each corresponding to one of said codes; means for selecting different ones of said selector positions codes; said selector position means being arranged in groups, each group corresponding to a different one of said signal intervals and including therein all the selector positions corresponding to codes having a signal of said second type in the corresponding signal interval; transmitter means normally operable to transmit a signal of said first type in each one of succeeding signal intervals and including a signal control means operable when connected to a selector position as selected by said selector means to substitute a signal of said second type for a signal of said first type; means counting the individual signal intervals and operable at each count to connect the signal control means to a different one of said groups in sequence.

2. In a telemetering system for selectively transmitting different ones of a plurality of different codes: each code having the same number of signal intervals, each code being preassigned to a different decimal digit and comprised of a different combination of a fixed number of a first and second type of signals, at least one of said codes having more than one signal of said second type; counting means for counting incoming pulses; decimal register means for registering the integrated count of incoming pulses and including a plurality of indicator means each corresponding to a different digit; said indicator means being arranged in groups, each group corresponding to a different one of said signal intervals and including therein all the indicating means corresponding to codes having a signal of said second type in the corresponding signal interval; indicator selector means operable in response to the counting means to select the indicator means corresponding to the integrated count; transmitter means normally operable to transmit a signal of said first type in each one of succeeding signal intervals and including a signal control means operable when connected to an indicator means as selected by said selector means to substitute a signal of said second type for a signal of said first type; means counting the individual signal intervals and operable at each count to connect the signal control means to a different one of said groups in sequence whereby the selected indicator means operates the signal control means during appropriate signal intervals to effect transmission of the preassigned code corresponding to the selected decimal digit.

3. In a telemetering system: a plurality of register means each operable to register in decimal digits a separate integrated count; a transmitter operable to be controlled by each register means to transmit signals of different codes, each code having the same number of signal intervals and comprising a different combination of a first and a second type of signal characteristic of the corresponding registered decimal count; means operable to start the transmitter; means individual to each register and operable to connect the coresponding register to control the transmitter; a momentary read-out switch .operable to operate the predetermined one of said connecting means and to cooperate with the operated connecting means to operate the start means; means respons1ve to operation of the predetermined connecting means to set up a circuit for operation of the next succeeding connecting means; means operable to reset the transmitter, the predetermined connecting means and the start means at the termination of the transmission of the signals corresponding to the registered count of the first connected register, and to maintain said set-up circuit; means in said transmitter responsive to reset of the transmitter to reset the reset means; circuit means responsive to operation of the circuit set-up means and the reset of the reset means to operate the next succeeding connecting means and to cooperate with the operated succeeding connecting means to operate the start means.

4. In a telemetering receiver: preliminary register means for registering an incoming code; relay means operable to determine the validity of the registered code; a plurality of main registers, each operable to register the code of the preliminary register when connected to be controlled by the preliminary register; code counting means operable at the end of each code to connect the preliminary register to a different one of the main registers; and means operable to reset the preliminary register at the end of each code after the corresponding main register has been operated.

5. In a telemetering system: transmitter means for serially transmitting a predetermined number of codes, each comprised of the same number of at least two different types of signals, the total number of one type having a fixed relationship with the total number of the other type, with the combination of signals varying from code to code as characterized by different metered values; receiver means including a preliminary register for registering a code as it is received; check means operable in response to the operation of the preliminary register in accordance with any one of said codes; a plurality of main registers, each operable to register the code of the preliminary register when connected to be controlled by the preliminary register; code counting means operable at the end of each code to connect the preliminary register to a different one of the main registers; and means operable to reset the preliminary register at the end of each code after the corresponding main register has been operated.

6. In a telemetering receiver: preliminmy register means for registering an incoming code; check means operable to determine the validity of the registered code; a plurality of main registers, each operable to register the code of the preliminary register when connected to be controlled by the preliminary register; code counting means operable at the end of each code to connect the preliminary register to a different one of the main registers; means operable to reset the preliminary register at the end of each code after the corresponding main register has been operated; a plurality of decoding means, each responsive to operation of one of the main registers; decoding indicator means operable to be connected to the decoding means for indicating the decoded value of the code in the corresponding main register; means controlled by said check means to be operable to connect the indicating means to the decoding means only when a predetermined number of valid codes have been serially registered in the preliminary register.

7. In a telemetering system for selectively transmitting different ones of a plurality of different binary selfchecking codes each having the same number of signal intervals, each code being preassigned to a different decimal digit and comprised of a different combination of a fixed number of each of a plurality of first and second type of signals; counting means for counting incoming pulses; decimal register means responsive to operation of the counting means for registering the integrated count of the incoming pulses; and relay means controlled by the register means for selectively transmitting different ones of said codes in accordance with the operation of the register means.

8. In a telemetering system for selectively transmitting different ones of a plurality of different binary selfchecking codes each having the same number of signal intervals, each code being preassigned to a different decimal digit and comprised of a different combination of a fixed number of each of a plurality of first and second type of signals; counting means for counting incoming pulses; decimal register means responsive to operation of the counting means for registering the integrated count of incoming pulses; relay means controlled by the register means for selectively transmitting different ones of said codes in accordance with the operation of the register means; and receiving means responsive to the transmitted signal from said transmitter means, said receiving means including means for checking the validity of the codes, and means for registering each valid code.

9. In a telemetering system for selectively transmitting different ones of a plurality of different binary self-checking codes each having the same number of signal intervals, each code being preassigned to a different decimal digit and comprised of a different combination of a fixed number of each of a plurality of first and second type of signals; counting means for counting incoming pulses; decimal register means responsive to operation of the counting means for registering the integrated count of incoming pulses; relay means controlled by the register means for selectively transmitting different ones of said codes in accordance With the operation of the register means; a plurality of stepping switch means, each corresponding to a different occurrence of said second type of signal, each stepping switch means including a plurality of fixed contacts each relating to a different one of said digits, and a movable contact member for scanning said positions in sequence; each of said plurality of fixed contacts comprised of subgroups, each subgroup corresponding to a different one of the said signal intervals and including all the fixed contacts corresponding to codes having a signal of said second type in the corresponding signal interval in the corresponding occurrence of said second signal; means connecting the movable contact means for ganged operation; conductor means connecting all the fixed contact means within each group to a different one of a group of conductors; an additional stepping switch means having a different one of a plurality of fixed contacts connected to each group conductor and having a movable contact member; means for counting input pulses and operable to operate said ganged movable contact means in accordance with the number of pulses received; a transmitter normally operable to transmit a signal of said first type in each one of a plurality of signal intervals and including a signal control means operable to substitute a signal of said second type for a signal of said first type in any one of said signal intervals; means for counting said pulses and operable to effect step-by-step operation of said additional stepping switch; circuit means including said additional stepping switch and said first stepping switch means for operating said control means to control the transmitter 011 predetermined ones of said signal interval in accordance with the position of the ganged movable contact member.

10. In a telemetering system, in combination, impulsing means for providing impulses in accordance with a measured quantity, counting means for providing a decimal count of said impulses, register means for registering said count in decimal digits, pulse sending means for transmitting pulses of a binary coded group of the same number of pulses for each digit of the registered count, said code comprising long and short pulses with all but the last pulse of each group designating the value of the digit and the last pulse being a check pulse, receiver means responsive to the transmitted pulses and comprising receiver register means for registering the coded signals, check means for determining the validity of the registered code, decoding indicator means controlled by the receiver register means for indicating the decoded value of the transmitted code, and said check means preventing the operation of the indicator means when an invalid code is received.

11. In a telemetering system, in combination, impulsing means for providing impulses in accordance with a measured quantity, counting means for providing a decimal count of said impulses, register means for registering said count in decimal digits, pulse sending means for transmitting a coded group or" five pulses for each digit of the registered count, each group containing three short pulses and two long pulses with the first four pulses designating the value of the digit and the last pulses being a check pulse, receiver means responsive to the transmitted pulses and comprising preliminary register means for registering the coded signals, check means for determining the validity of the registered code, main register means controlled by the check means, and decoding indicator means operated by the main register means for indicating the decoded value of the transmitted code.

References Qited in the file of this patent UNITED STATES PATENTS 2,088,793 Judge Aug. 3, 1937 2,344,231 Burns Mar. 14, 1944 2,372,593 McWhirter Mar. 27, 1945 2,395,693 Sorensen Feb. 26, 1946 2,399,734 Hailes et a1. May 7, 1946 2,600,729 Boyer et a1 June 17, 1952 2,644,931 Derr July 7, 1953 2,674,734 McCreary Apr. 6, 1954 2,679,034 Albrighton May 18, 1954 2,680,240 Greenfield June 1, 1954 2,739,298 Lovell Mar. 20, 1956 2,749,535 Cruess June 5, 1956 2,966,659 Dahlbom Dec. 27, 1960 

1. IN A CODING SYSTEM FOR SELECTIVELY TRANSMITTING A PLURALITY OF DIFFERENT CODES: EACH CODE HAVING THE SAME NUMBER OF SIGNAL INTERVALS, EACH CODE COMPRISED OF A DIFFERENT COMBINATION OF A FIRST AND SECOND TYPE OF SIGNALS REPRESENTING A DECIMAL DIGIT, AT LEAST ONE OF SAID CODES HAVING MORE THAN ONE SIGNAL OF SAID SECOND TYPE; A PLURALITY OF SELECTOR POSITIONS, EACH CORRESPONDING TO ONE OF SAID CODES; MEANS FOR SELECTING DIFFERENT ONES OF SAID SELECTOR POSITIONS CODES; SAID SELECTOR POSITION MEANS BEING ARRANGED IN GROUPS, EACH GROUP CORRESPONDING TO A DIFFERENT ONE OF SAID SIGNAL INTERVALS AND INCLUDING THEREIN ALL THE SELECTOR POSITIONS CORRESPONDING TO CODES HAVING A SIGNAL OF SAID SECOND TYPE IN THE CORRESPONDING SIGNAL INTERVAL; TRANSMITTER MEANS NORMALLY OPERABLE TO TRANSMIT A SIGNAL OF SAID FIRST TYPE IN EACH ONE OF SUCCEEDING SIGNAL INTERVALS AND INCLUDING A SIGNAL CONTROL MEANS OPERABLE WHEN CONNECTED TO A SELECTOR POSITION AS SELECTED BY SAID SELECTOR MEANS TO SUBSTITUTE A SIGNAL OF SAID SECOND TYPE FOR A SIGNAL OF SAID FIRST TYPE; MEANS COUNTING THE INDIVIDUAL SIGNAL INTERVALS AND OPERABLE AT EACH COUNT TO CONNECT THE SIGNAL CONTROL MEANS TO A DIFFERENT ONE OF SAID GROUPS IN SEQUENCE. 